• Advances in materials Research
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• v.2 no.4
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• pp.209-219
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• 2013

We have described primary studies on conductivity and molecular weight of polyaniline separately in the electric and magnetic fields when it is used in a field effect experimental configuration. We report further studies on doped in-situ deposited polyaniline. First we have chemically synthesized polyaniline by ammonium peroxodisulfate in acidic aques and organic solutions at different times. Then we measured mass and conductivity and obtained the best time of polymerizations. In continue, we repeated these reactions separately under different electric and magnetic fields in constant time and measured mass and conductivity. The polyaniline is characterized by gel permeation chromatography (GPC), UV-Visible spectroscopy and electrical conductivity. High molecular weight polyanilines are synthesized under electric field, $M_w$ = 520000-680000 g/mol, with $M_w/M_n$ = 2-2.5. The UV-Visible spectra of polyanilines oxidized by ammonium peroxodisulfate and protonated with dodecylbenzenesulfonic acid (PANi-DBSA), in N-methylpyrolidone (NMP), show a smeared polaron peak shifted into the visible. Electrical conductivity of polyanilines has been studied by four-probe method. The conductivity of the films of emeraldine protonated by DBSA cast from NMP are higher than 500 and 25 S/cm under 10 KV/m of potential) electric field and 0.1 T magnetic field, respectively. It shows an enhanced resistance to ageing too. By the next steps, we carried chemical polymerization at the best electric and magnetic fields at different times. Finally, resulted in finding the best time and amount of the fields. The longer polymerization time and the higher magnetic field can lead to degradation of polyaniline films and decrease conductivity and molecular mass.

• The Korean Journal of Food And Nutrition
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• v.28 no.5
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• pp.933-940
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• 2015

The objective of this study was to determine quality changes in seed germination rates and lipid components in Japonica and Tongil (indica/japonica) type brown rices with different tocol composition during storage. Moisture content, seed germination rate, crude lipid content, fat acidity, tocol content, free fatty acid composition of brown rice and pH of milled rice were measured to evaluate their quality after storage. Seed germination rates of stored Japonica and Tongil type brown rices were decreased by 22.4% and 59.7%, respectively, after 8 weeks of storage. The fat acidity of Japonica rice was significantly (p<0.05) higher than that of Tongil type brown rices after storage. The major tocol homologue of Tongil type was ${\gamma}-tocotrienol$, whereas, major tocol homologues of Japonica brown rices were ${\alpha}-tocopherol$ and ${\alpha}-tocotrienol$ throughout the entire storage period.

• Journal of Animal Science and Technology
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• v.58 no.6
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• pp.23.1-23.17
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• 2016

Background: The functionality of myofibrillar proteins is a major factor influencing the quality attributes of muscle foods. Nonetheless, the relationships between muscle type and oxidative changes in chevon during ageing are meagrely elucidated. Postmortem changes in antioxidant status and physicochemical properties of glycolytic gluteus medius (GM) and oxidative infraspinatus (IS) muscles in goats were compared. Methods: Twenty Boer bucks (9-10 months old, body weight of $36.9{\pm}0.725kg$) were slaughtered and the carcasses were subjected to chill storage ($4{\pm}0.5^{\circ}C$). Analyses were conducted on GM and IS muscles sampled on 0, 1, 4 and 7 d postmortem. Results: Chill storage did not affect the antioxidant enzyme activities in both muscles. The IS had greater (P < 0.05) superoxide dismutase and catalase activities than GM. Carotenoid and tocopherol contents did not differ between muscles but decreased (P < 0.05) over storage. The IS had higher (P < 0.05) glycogen and ultimate pH and lower (P < 0.05) shear force and cooking loss than GM. The carbonyl content, % metmyoglobin, drip loss and TBARS increased (P <0.05) while free thiol, metmyoglobin reducing activity (MRA), shear force and myoglobin decreased (P < 0.05) over storage. Muscle type had no effect (P > 0.05) on free thiol, MRA and TBARS. The GM had lower (P < 0.05) redness on d 0 and 1 than IS while the IS had greater carbonyl, % metmyoglobin and drip loss than GM on d 7. The reflective density of slow myosin heavy chain (MHC) was higher (P < 0.05) while the density of fast MHC and actin was lower (P < 0.05) in IS than GM. Regardless of muscle type, the density of MHC decreased (P < 0.05) while that of actin was stable over storage. Nonetheless, the degradation of fast and slow MHC was greater (P < 0.05) in IS than GM. Muscle type had no effect (P > 0.05) on consumer preference for flavour, juiciness and overall acceptability. However, IS had higher (P < 0.05) tenderness score than GM on d 1 and 4 postmortem. Intramuscular fat was higher (P< 0.05) in IS compared with GM. Fatty acid composition did not differ between the muscles. However, GM had lower (P < 0.05) n-6/n-3 ratio than IS. The n-3 and n-6 PUFA declined (P < 0.05) while the SFA increased (P < 0.05) over storage. Conclusion: The changes in myofibrillar proteins and physicochemical properties of goat meat during postmortem chill storage are muscle-dependent.

• Korean Chemical Engineering Research
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• v.53 no.3
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• pp.357-363
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• 2015

The development of the environment-friendly tire that meets the standard requirements according to tire labeling system can be improved through using highly homogeneous silica immobilized zinc oxide nanoparticles. In this study, a considerable amount of nanoporous silica was essentially added into nano zinc oxide to improve the physiochemical properties of the formed composite. The introduction of nanoporous silica materials in the composite facilitates the improvement of the wear-resistance and increases the elasticity of the tread. Therefore, the introduction of nanoporous silica can replace carbon black as filler in the formation of composites with desirable properties for conventional green tire. Herein, mesoporous silica immobilized zinc oxide nanoparticle with desirable properties for rubber compounds was investigated. Composites with homogeneous dispersion were obtained in the absence of dispersants. The dispersion stability was controlled through varying the molar ratio, ageing time and mixing order of the reactants. A superior dispersion was achieved in the sample obtained using 0.03 mol of zinc precursor as it had the smallest grain size (50.5 nm) and then immobilized in silica aged for 10 days. Moreover, the specific surface area of this sample was the highest ($649m^2/g$).

• Journal of Life Science
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• v.24 no.5
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• pp.467-475
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• 2014

Sea buckthorn (Hippophae rhamnoides L.) is a well-known and rich source of biologically active compounds, such as flavonoids, carotenoids, steroids, vitamins, tannins, and oleic acid. The effects of sea buckthorn fruit extract (SBFE) on ultraviolet (UV)-induced cell death was investigated in SK-MEL-2 cells cotreated with UV and a low concentration (LoC), medium concentration (MeC), or high concentration (HiC) of SBFE. Cell viability gradually decreased in accordance with an increase in the UV dose. The cell viability of the UV+SBFE cotreated cells increased significantly compared to that of UV+vehicle-treated cells during the application of an appropriate UV radiation dose (400 mJ). In addition, the number of 4',6-diamidino-2-phenylindole (DAPI), propidium iodine (PI)-, and annexin V-stained apoptotic cells was higher in the UV+vehicle-treated cells than in the UV untreated cells. The decrease of apoptotic cell numbers varied in each treated group, but it was most significant in the SBFE-treated group. The number of PI-stained cells dramatically decreased in accordance with the concentration of SBFE, and the maximum decrease was detected in the UV+HiC-treated group. In addition, Bax expression increased and Bcl-2 expression decreased in the SBFE-treated group compared with the UV-only treated group. The level of caspase-3 remained constant in all the groups. These results suggest that SBFE may contribute to a recovery from UV-induced cell death through the regulation of apoptotic protein expression and that it may have potential therapeutic utility in ameliorating UV-induced skin ageing.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.659-666
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• 2004

This study was conducted to assess objective and subjective meat quality traits for imported chilled beef with a high degree of marbling in longissimus muscle with reference to Hanwoo beef Muscle samples of four Wagyu, four Angus, four Hanwoo grade 1, and three Hanwoo grade 3 were purchased from a commercial beef market. The meats had intramuscular fat content of approximately 22, 8, 13 and 4%, and aged for 31, 71, 14 and 14 days, respectively. Imported beef showed a significantly(P<0.05) lower WB-shear force than Hanwoo. However, the instrument measurement did not reflect sensory tenderness and juiciness, which were similar between the four groups. On the other hand, Hanwoo beef showed significantly(P<0.05) favorable flavor intensity. This was likely an indication of more a desirable eating quality for Hanwoo beef, regardless of the level of intramuscular fat content. Discriminant functions of C18: 0, C18: In-7, C18: In-9, C20: 3n-6, C20 : 4n-6 and total n-3 polyunsaturated fatty acids classified the domestic and foreign beef products at 100%, despite a noticeable difference between two groups existed only in C18:0. Principle component analysis indicated that subjective flavor intensity was negatively related to C18: 0 and C18: ln-7. The result indicated that C18: 0 could be a possible candidate fatty acid for difference in flavor intensity between two beef groups. The current study demonstrated that the domestic product was more acceptable for Korean consumers. However, it was not identified whether the result was associated with breed, feeding regime, or ageing time. Further studies are required for breed specification in terms of sensory characteristics and consumer preference.